LASS2 enhances chemosensitivity to cisplatin by inhibiting PP2A-mediated ß-catenin dephosphorylation in a subset of stem-like bladder cancer cells.

BACKGROUND: The benefits of first-line, cisplatin-based chemotherapy for muscle-invasive bladder cancer are limited due to intrinsic or acquired resistance to cisplatin. Increasing evidence has revealed the implication of cancer stem cells in the development of chemoresistance. However, the underlying molecular mechanisms remain to be elucidated. This study investigates the role of LASS2, a ceramide synthase, in regulating Wnt/ß-catenin signaling in a subset of stem-like bladder cancer cells and explores strategies to sensitize bladder cancer to cisplatin treatment. METHODS: Data from cohorts of our center and published datasets were used to evaluate the clinical characteristics of LASS2. Flow cytometry was used to sort and analyze bladder cancer stem cells (BCSCs). Tumor sphere formation, soft agar colony formation assay, EdU assay, apoptosis analysis, cell viability, and cisplatin sensitivity assay were used to investigate the functional roles of LASS2. Immunofluorescence, immunoblotting, coimmunoprecipitation, LC-MS, PCR array, luciferase reporter assays, pathway reporter array, chromatin immunoprecipitation, gain-of-function, and loss-of-function approaches were used to investigate the underlying mechanisms. Cell- and patient-derived xenograft models were used to investigate the effect of LASS2 overexpression and a combination of XAV939 on cisplatin sensitization and tumor growth. RESULTS: Patients with low expression of LASS2 have a poorer response to cisplatin-based chemotherapy. Loss of LASS2 confers a stem-like phenotype and contributes to cisplatin resistance. Overexpression of LASS2 results in inhibition of self-renewal ability of BCSCs and increased their sensitivity to cisplatin. Mechanistically, LASS2 inhibits PP2A activity and dissociates PP2A from ß-catenin, preventing the dephosphorylation of ß-catenin and leading to the accumulation of cytosolic phospho-ß-catenin, which decreases the transcription of the downstream genes ABCC2 and CD44 in BCSCs. Overexpression of LASS2 combined with a tankyrase inhibitor (XAV939) synergistically inhibits tumor growth and restores cisplatin sensitivity. CONCLUSIONS: Targeting the LASS2 and ß-catenin pathways may be an effective strategy to overcome cisplatin resistance and inhibit tumor growth in bladder cancer patients.

Inhibition of Sema4D attenuates pressure overload-induced pathological myocardial hypertrophy via the MAPK/NF-κB/NLRP3 pathways.

Sema4D (CD100) is closely related to pathological and physiological processes, including tumor growth, angiogenesis and cardiac development. Nevertheless, the role and mechanism of Sema4D in cardiac hypertrophy are still unclear to date. To assess the impact of Sema4D on pathological cardiac hypertrophy, TAC surgery was performed on C57BL/6 mice which were transfected with AAV9-mSema4D-shRNA or AAV9-mSema4D adeno-associated virus by tail vein injection. Our results indicated that Sema4D knockdown mitigated cardiac hypertrophy, fibrosis and dysfunction when exposed to pressure overload, and Sema4D downregulation markedly inhibited cardiomyocyte hypertrophy induced by angiotensin II. Meanwhile, Sema4D overexpression had the opposite effect in vitro and in vivo. Furthermore, analysis of signaling pathways showed that Sema4D activated the MAPK pathway during cardiac hypertrophy induced by pressure overload, and the pharmacological mitogen-activated protein kinase kinase 1/2 inhibitor U0126 almost completely reversed Sema4D overexpression-induced deteriorated phenotype, resulting in improved cardiac function. Further research indicated that myocardial hypertrophy induced by Sema4D was closely related to the expression of the pyroptosis-related proteins PP65, NLRP3, caspase-1, ASC, GSDMD, IL-18 and IL-1ß. In conclusion, our study demonstrated that Sema4D regulated the process of pathological myocardial hypertrophy through modulating MAPK/NF-κB/NLRP3 pathway, and Sema4D may be the promising interventional target of cardiac hypertrophy and heart failure.

Downregulation of B4GALT5 attenuates cardiac fibrosis through Lumican and Akt/GSK-3ß/ß-catenin pathway.

Virtually all forms of cardiac disease exhibit cardiac fibrosis as a common trait, which ultimately leads to adverse ventricular remodeling and heart failure. To improve the prognosis of heart disease, it is crucial to halt the progression of cardiac fibrosis. Protein function is intricately linked with protein glycosylation, a vital post-translational modification. As a fundamental member of the ß1,4-galactosyltransferase gene family (B4GALT), ß1,4-galactosyltransferase V (B4GALT5) is associated with various disorders. In this study, significant levels of B4GALT5 expression were observed in cardiac fibrosis induced by transverse aortic constriction (TAC) or TGFß1 and the activation of cardiac fibroblasts (CFs). Subsequently, by administering AAV9-shB4GALT5 injections to TAC animals, we were able to demonstrate that in vivo B4GALT5 knockdown decreased the transformation of CFs into myofibroblasts (myoFBs) and reduced the deposition of cardiac collagen fibers. In vitro tests revealed the same results. Conversely, both in vivo and in vitro experiments indicated that overexpression of B4GALT5 stimulates CFs activation and exacerbates cardiac fibrosis. Initially, we elucidated the primary mechanism by which B4GALT5 regulates the Akt/GSK-3ß/ß-catenin pathway and directly interacts with laminin, thereby affecting cardiac fibrosis. Our findings demonstrate that B4GALT5 promotes cardiac fibrosis through the Akt/GSK-3ß/ß-catenin pathway and reveal laminin as the target protein of B4GALT5.

UGCG modulates heart hypertrophy through B4GalT5-mediated mitochondrial oxidative stress and the ERK signaling pathway.

Mechanical pressure overload and other stimuli often contribute to heart hypertrophy, a significant factor in the induction of heart failure. The UDP-glucose ceramide glycosyltransferase (UGCG) enzyme plays a crucial role in the metabolism of sphingolipids through the production of glucosylceramide. However, its role in heart hypertrophy remains unknown. In this study, UGCG was induced in response to pressure overload in vivo and phenylephrine stimulation in vitro. Additionally, UGCG downregulation ameliorated cardiomyocyte hypertrophy, improved cardiomyocyte mitochondrial oxidative stress, and reduced the ERK signaling pathway. Conversely, UGCG overexpression in cardiomyocytes promoted heart hypertrophy development, aggravated mitochondrial oxidative stress, and stimulated ERK signaling. Furthermore, the interaction between beta-1,4-galactosyltransferase 5 (B4GalT5), which catalyses the synthesis of lactosylceramide, and UGCG was identified, which also functions as a synergistic molecule of UGCG. Notably, limiting the expression of B4GalT5 impaired the capacity of UGCG to promote myocardial hypertrophy, suggesting that B4GalT5 acts as an intermediary for UGCG. Overall, this study highlights the potential of UGCG as a modulator of heart hypertrophy, rendering it a potential target for combating heart hypertrophy.

Medicarpin induces G1 arrest and mitochondria-mediated intrinsic apoptotic pathway in bladder cancer cells.

Bladder cancer (BC) is the tenth most commonly diagnosed cancer. High recurrence, chemoresistance, and low response rate hinder the effective treatment of BC. Hence, a novel therapeutic strategy in the clinical management of BC is urgently needed. Medicarpin (MED), an isoflavone from Dalbergia odorifera, can promote bone mass gain and kill tumor cells, but its anti-BC effect remains obscure. This study reve aled that MED effectively inhibited the proliferation and arrested the cell cycle at the G1 phase of BC cell lines T24 and EJ-1 in vitro. In addition, MED could significantly suppress the tumor growth of BC cells in vivo. Mechanically, MED induced cell apoptosis by upregulating pro-apoptotic proteins BAK1, Bcl2-L-11, and caspase-3. Our data suggest that MED suppresses BC cell growth in vitro and in vivo via regulating mitochondria-mediated intrinsic apoptotic pathways, which can serve as a promising candidate for BC therapy.

FGF5 protects heart from sepsis injury by attenuating cardiomyocyte pyroptosis through inhibiting CaMKII/NFκB signaling.

Sepsis accompanied by myocardial injury is an important cause of multiple organ dysfunction, and its underlying molecular mechanism is not fully clear. Although diverse effects of fibroblast growth factor (FGF) in heart have been discovered till now, the specific role of FGF5 in heart remains unclear. Therefore, our study aims to explore the possible impacts of FGF5 on sepsis-induced cardiac injury. Sepsis-induced cardiac injury was established through administration of lipopolysaccharide (LPS). The expression level of FGF5 in sepsis heart was decreased, and injection of FGF5-overexpressing adenovirus attenuated cardiac injury reflected by echocardiographic and pathological findings. Besides, FGF5 overexpression, not only in vivo heart but also in vitro cardiomyocytes, reduced the levels of oxidative stress and pyroptosis resulted from LPS. In addition, overexpression of FGF5 reduced LPS-activated the levels of phosphorylated CaMKII (p-CaMKII), p-NFκB, NLRP3, caspase-1, IL-1ß and IL-18. Furthermore, KN93, the inhibitor of CaMKII, exerted the similarly protective effects on LPS-induced pyroptosis. In summary, our study implied the beneficial effects of FGF5 on LPS-induced cardiac injury, which was at least partially attributed to the inhibition of CaMKII-mediated pyroptotic signaling.

Galangin inhibits neointima formation induced by vascular injury via regulating the PI3K/AKT/mTOR pathway.

Aims: The proliferation and migration of vascular smooth muscle cells (VSMCs) play vital roles in the pathological process of neointima formation after vascular injury. Galangin, an extract of the ginger plant galangal, is involved in numerous biological activities, including inhibiting the proliferation and migration of tumor cells, but its effect on VSMCs is unknown. This study focused on the role and mechanism of galangin in the neointima formation induced by vascular injury. Methods and results: In this study, we found that galangin restrained the PDGF-BB-induced proliferation, migration and phenotypic switching of VSMCs in a concentration-dependent manner. In vivo, we established a model of carotid artery balloon injury in rats, followed by intragastric administration of galangin (40 mg kg-1 day-1 or 80 mg kg-1 day-1) for 14 or 28 consecutive days. Then, the degree of neointima hyperplasia was evaluated by H&E staining, and the level of relevant protein expression was assessed by immunofluorescence and western blotting. In vitro, we isolated and grew primary rat aortic smooth muscle cells, which were treated with PDGF-BB and different doses of galangin, and then CCK-8 assay, wound healing assay, transwell assay, western blotting and immunofluorescence assays were performed. We found that galangin significantly inhibited PDGF-BB-induced proliferation, migration, and phenotypic switching of VSMCs and promoted autophagy in VSMCs in vitro, and galangin significantly inhibited neointimal hyperplasia after the common carotid artery balloon injury in rats. In terms of mechanisms, galangin inhibited the PI3K/AKT/mTOR pathway, thereby suppressing VSMC's switch from a contractile to a synthetic phenotype, inhibiting VSMC proliferation, migration and phenotypic switching and upregulating the Beclin1 protein expression levels and the ratio of LC3BII/I, promoting VSMC autophagy, and thereby inhibiting neointimal hyperplasia after vascular injury. Conclusion: Our study suggests that galangin inhibits neointimal hyperplasia after vascular injury by inhibiting smooth muscle cell proliferation, migration and phenotypic switching and by promoting autophagy, and that galangin may be a promising drug for the prevention and treatment of vascular restenosis after PCI.

FGF5 alleviated acute lung injury via AKT signal pathway in endothelial cells.

Acute lung injury (ALI), with high morbidity and mortality, is mainly resulted by infectious or non-infectious inflammatory stimulators, and it will further evolve into acute respiratory distress syndrome if not controlled. Fibroblast growth factors (FGFs) consist of more than 23 kinds of members, which are involved in various pathophysiological processes of body. However, the effect of FGF5, one member of FGFs, is still not certain in lipopolysaccharide (LPS)-induced ALI. In this study, we explored the possible impacts of FGF5 in LPS-induced ALI and primarily focused on endothelial cell, which was one of the most vulnerable cells in septic ALI. In the mouse group of FGF5 overexpression, LPS-induced lung injuries were mitigated, as well as the pyroptosis levels of pulmonary vascular endothelial cells. Additionally, in vitro human umbilical vein endothelial cells (HUVECs), our results showed that the level of cell pyroptosis was ameliorated with FGF5 overexpression, and AKT signal was activated with the overexpression of FGF5, whereas after administration of MK2206, an inhibitor of AKT signal, the protection of FGF5 was inhibited. Therefore, these results suggested that FGF5 exerted protective effects in endothelial cells exposed to LPS, and this protection of FGF5 could be attributed to activated AKT signal.

Fibroblast growth factor 5 overexpression ameliorated lipopolysaccharide-induced apoptosis of hepatocytes through regulation of the phosphoinositide-3-kinase/protein kinase B pathway.

BACKGROUND: Sepsis is a systemic inflammatory syndrome induced by several infectious agents. Multiple organs are affected by sepsis, including the liver, which plays an important role in metabolism and immune homeostasis. Fibroblast growth factors (FGFs) participate in several biological processes, although the role of FGF5 in sepsis is unclear. METHODS: In this study, lipopolysaccharide (LPS) was administrated to mice to establish a sepsis-induced liver injury. A similar in vitro study was conducted using L-02 hepatocytes. Western blot and immunohistochemistry staining were performed to evaluate the FGF5 expression level in liver tissues and cells. Inflammatory cell infiltrations, cleaved-caspase-3 expressions, reactive oxygen species and levels of inflammatory cytokines were detected by immunofluorescence, dihydroethidium staining, and reverse transcription quantitative polymerase chain reaction analysis, respectively. Flow cytometry was used to detect the apoptosis level of cells. In addition, ribonucleic acid (RNA)-sequencing was applied to explore the possible mechanism by which FGF5 exerted effects. RESULTS: LPS administration caused FGF5 down-regulation in the mouse liver as well as in L-02 hepatocytes. Additionally, with FGF5 overexpression, liver injury and the level of hepatocyte apoptosis were ameliorated. Further, RNA sequencing performed in hepatocytes revealed the phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) pathway as a possible pathway regulated by FGF5 . This was supported using an inhibitor of the PI3K/AKT pathway, which abrogated the protective effect of FGF5 in LPS-induced hepatocyte injury. CONCLUSION: The anti-apoptotic effect of FGF5 on hepatocytes suffering from LPS has been demonstrated and was dependent on the activation of the PI3K/AKT signaling pathway.

[Effect of SO2 volume fraction in flue gas on the adsorption behaviors adsorbed by ZL50 activated carbon and kinetic analysis].

The influence of SO2 dynamic adsorption behaviors using ZL50 activated carbon for flue gas desulphurization and denitrification under different SO2 volume fraction was investigated experimentally, and the kinetic analysis was conducted by kinetic models. With the increase of SO2 volume fraction in flue gas, the SO2 removal ratio and the activity ratio of ZL50 activated carbon decreased, respectively, and SO2 adsorption rate and capacity increased correspondingly. The calculated results indicate that Bangham model has the best prediction effect, the chemisorption processes of SO2 was significantly affected by catalytic oxidative reaction. The adsorption rate constant of Lagergren's pseudo first order model increased with the increase of inlet SO, volume fraction, which indicated that catalytic oxidative reaction of SO2 adsorbed by ZL50 activated carbon may be the rate controlling step in earlier adsorption stage. The Lagergren's and Bangham's initial adsorption rate were deduced and defined, respectively. The Ho's and Elovich's initial adsorption rate were also deduced in this paper. The Bangham's initial adsorption rate values were defined in good agreement with those of experiments. The defined Bangham's adsorptive reaction kinetic model can describe the SO2 dynamic adsorption rate well. The studied results indicated that the SO2 partial order of initial reaction rate was one or adjacent to one, while the O2 and water vapor partial order of initial reaction rate were constants ranging from 0.15-0.20 and 0.45-0.50, respectively.

Synthesis of biodiesel from a model waste oil feedstock using a carbon-based solid acid catalyst: reaction and separation.

A solid acid catalyst that can keep high activity and stability is necessary when low cost feedstocks are utilized for biodiesel synthesis because the reaction medium contains a large amount of water. Three solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and petroleum asphalt. The structure of these catalysts was characterized by a variety of techniques. A new process that used the coupling of the reaction and separation was employed, which greatly improved the conversion of cottonseed oil (triglyceride) and free fatty acids (FFA) when a model waste oil feedstock was used. The vegetable oil asphalt-based catalyst showed the highest catalytic activity. This was due to the high density and stability of its acid sites, its loose irregular network, its hydrophobicity that prevented the hydration of -OH species, and large pores that provided more acid sites for the reactants.